DMPlex: Made DMPlexGetNumFaceVertices() externally visible
package.py: add support for cloning from Git
Git download: ML, SuperLU_DIST, MUMPS, ctetgen
SuperLU_DIST.py: upgrade to pre-release version 3.3
TSEIMEX: import extrapolated IMEX from mercurial repository

Contributions from: Emil Constantinescu <emconsta@mcs.anl.gov>
Merge branch 'master' into jed/ts-eimex

Sync to include Git conversion, PETSC_EXTERN, and minor API changes.

Conflicts:
	src/ts/interface/tsregall.c
Implementation of the Extrapolated IMEX schemes - initial push.
Merge branch 'emil/ts-new-scheme-eimex' of bitbucket:emconsta/petscForkEIMEX into jed/ts-eimex

Essentially just moves example files to src/ts/examples/tutorials/eimex/

* 'emil/ts-new-scheme-eimex' of bitbucket:emconsta/petscForkEIMEX:
  Implementation of the Extrapolated IMEX schemes - initial push.

Conflicts:
	src/ts/impls/eimex/eimex.c
	src/ts/impls/eimex/makefile
TSEIMEX: use makefile targets for running examples
Updated and tested eimex examples
fixed ts typo
fixed small ts typo
fixed the starting procedure in arkimex for DAEs to handle snes properly
removed XXXRegisterDynamic() but kept the APIs for everything else underneath the same
phase I of the update to handling registering function pointers
removed path argument to XXXInitializePackage() and XXXRegister()
removed path and MPI_Comm arguments from PetscFunctionListFind/Add()
Addressed Barry's comments from the pull request for eimex.c
Addressed Barry's comments from the EIMEX pull request for the EIMEX tutorials
developers.tex: update documentation of PetscObjectComposeFunction
changes: document PetscFunctionListAdd() API change